Don't error out when progression order is invalid. #186

Instead of a regular dictionary for the display of progression order,
use a subclass of defaultdict instead.  The defaultdict's __missing__
method is overridden to supply a custom error message that used the
offending key.  Everybody wins!!!

glymur/codestream.py

@@ -17,6 +17,7 @@ codestreams.
 # the base Segment class.
 # pylint: disable=R0903
 
+import collections
 import math
 import struct
 import sys
@@ -30,12 +31,26 @@ from .core import WAVELET_XFORM_5X3_REVERSIBLE
 from .core import _CAPABILITIES_DISPLAY
 from .lib import openjp2 as opj2
 
-_PROGRESSION_ORDER_DISPLAY = {
+class _keydefaultdict(collections.defaultdict):
-    LRCP: 'LRCP',
+    """Unlisted keys help form their own error message.
+
+    Normally defaultdict uses a factory function with no input arguments, but
+    that's not quite the behavior we want.
+    """
+    def __missing__(self, key):
+        if self.default_factory is None:
+            raise KeyError(key)
+        else:
+            ret = self[key] = self.default_factory(key)
+            return ret
+
+_factory = lambda x:  '{0} (invalid)'.format(x)
+_PROGRESSION_ORDER_DISPLAY = _keydefaultdict(_factory,
+        { LRCP: 'LRCP',
           RLCP: 'RLCP',
           RPCL: 'RPCL',
           PCRL: 'PCRL',
-    CPRL: 'CPRL'}
+          CPRL: 'CPRL'})
 
 _WAVELET_TRANSFORM_DISPLAY = {
     WAVELET_XFORM_9X7_IRREVERSIBLE: '9-7 irreversible',
@@ -371,6 +386,9 @@ class Codestream(object):
         numbytes = offset + 2 + length - fptr.tell()
         spcod = fptr.read(numbytes)
         spcod = np.frombuffer(spcod, dtype=np.uint8)
+        if spcod[0] not in [LRCP, RLCP, RPCL, PCRL, CPRL]:
+            msg = "Invalid progression order in COD segment: {0}."
+            warnings.warn(msg.format(spcod[0]))
 
         sop = (scod & 2) > 0
         eph = (scod & 4) > 0

glymur/test/fixtures.py

@@ -587,3 +587,26 @@ issue_183_colr = """Colour Specification Box (colr) @ (62, 12)
     Method:  restricted ICC profile
     Precedence:  0
     ICC Profile:  None"""
+        
+
+# Progression order is invalid.
+issue_186_progression_order = """COD marker segment @ (174, 12)
+    Coding style:
+        Entropy coder, without partitions
+        SOP marker segments:  False
+        EPH marker segments:  False
+    Coding style parameters:
+        Progression order:  33 (invalid)
+        Number of layers:  1
+        Multiple component transformation usage:  reversible
+        Number of resolutions:  6
+        Code block height, width:  (32 x 32)
+        Wavelet transform:  9-7 irreversible
+        Precinct size:  default, 2^15 x 2^15
+        Code block context:
+            Selective arithmetic coding bypass:  False
+            Reset context probabilities on coding pass boundaries:  False
+            Termination on each coding pass:  False
+            Vertically stripe causal context:  False
+            Predictable termination:  False
+            Segmentation symbols:  False"""

glymur/test/test_codestream.py

@@ -29,8 +29,39 @@ class TestCodestream(unittest.TestCase):
     def tearDown(self):
         pass
 
+    def test_siz_segment_ssiz_unsigned(self):
+        """ssiz attribute to be removed in future release"""
+        j = Jp2k(self.jp2file)
+        codestream = j.get_codestream()
+
+        # The ssiz attribute was simply a tuple of raw bytes.
+        # The first 7 bits are interpreted as the bitdepth, the MSB determines
+        # whether or not it is signed.
+        self.assertEqual(codestream.segment[1].ssiz, (7, 7, 7))
+
+
 @unittest.skipIf(OPJ_DATA_ROOT is None,
                  "OPJ_DATA_ROOT environment variable not set")
+class TestCodestreamOpjData(unittest.TestCase):
+    """Test suite for unusual codestream cases.  Uses OPJ_DATA_ROOT"""
+
+    def setUp(self):
+        self.jp2file = glymur.data.nemo()
+
+    def tearDown(self):
+        pass
+
+    def test_invalid_progression_order(self):
+        """Should still be able to parse even if prog order is invalid."""
+        jfile = opj_data_file('input/nonregression/2977.pdf.asan.67.2198.jp2')
+        if sys.hexversion < 0x03000000:
+            with warnings.catch_warnings():
+                warnings.simplefilter("ignore")
+                Jp2k(jfile)
+        else:
+            with self.assertWarns(UserWarning):
+                Jp2k(jfile)
+
     def test_tile_height_is_zero(self):
         """Zero tile height should not cause an exception."""
         filename = opj_data_file('input/nonregression/2539.pdf.SIGFPE.706.1712.jp2')
@@ -43,8 +74,6 @@ class TestCodestream(unittest.TestCase):
                 Jp2k(filename)
 
 
-    @unittest.skipIf(OPJ_DATA_ROOT is None,
-                     "OPJ_DATA_ROOT environment variable not set")
     @unittest.skipIf(os.name == "nt", "Temporary file issue on window.")
     def test_reserved_marker_segment(self):
         """Reserved marker segments are ok."""
@@ -76,8 +105,6 @@ class TestCodestream(unittest.TestCase):
             self.assertEqual(codestream.segment[2].length, 3)
             self.assertEqual(codestream.segment[2].data, b'\x00')
 
-    @unittest.skipIf(OPJ_DATA_ROOT is None,
-                     "OPJ_DATA_ROOT environment variable not set")
     @unittest.skipIf(sys.hexversion < 0x03020000,
                      "Uses features introduced in 3.2.")
     @unittest.skipIf(os.name == "nt", "Temporary file issue on window.")
@@ -109,8 +136,6 @@ class TestCodestream(unittest.TestCase):
                 self.assertEqual(codestream.segment[2].length, 3)
                 self.assertEqual(codestream.segment[2].data, b'\x00')
 
-    @unittest.skipIf(OPJ_DATA_ROOT is None,
-                     "OPJ_DATA_ROOT environment variable not set")
     def test_psot_is_zero(self):
         """Psot=0 in SOT is perfectly legal.  Issue #78."""
         filename = os.path.join(OPJ_DATA_ROOT,
@@ -123,19 +148,6 @@ class TestCodestream(unittest.TestCase):
         self.assertEqual(codestream.segment[-1].marker_id, 'EOC')
 
 
-    def test_siz_segment_ssiz_unsigned(self):
-        """ssiz attribute to be removed in future release"""
-        j = Jp2k(self.jp2file)
-        codestream = j.get_codestream()
-
-        # The ssiz attribute was simply a tuple of raw bytes.
-        # The first 7 bits are interpreted as the bitdepth, the MSB determines
-        # whether or not it is signed.
-        self.assertEqual(codestream.segment[1].ssiz, (7, 7, 7))
-
-
-    @unittest.skipIf(OPJ_DATA_ROOT is None,
-                     "OPJ_DATA_ROOT environment variable not set")
     def test_siz_segment_ssiz_signed(self):
         """ssiz attribute to be removed in future release"""
         filename = os.path.join(OPJ_DATA_ROOT, 'input/conformance/p0_03.j2k')

glymur/test/test_printing.py

@@ -645,6 +645,18 @@ class TestPrintingOpjDataRoot(unittest.TestCase):
     def tearDown(self):
         pass
 
+    def test_invalid_progression_order(self):
+        """Should still be able to print even if prog order is invalid."""
+        jfile = opj_data_file('input/nonregression/2977.pdf.asan.67.2198.jp2')
+        with warnings.catch_warnings():
+            warnings.simplefilter("ignore")
+            jp2 = Jp2k(jfile)
+        codestream = jp2.get_codestream()
+        with patch('sys.stdout', new=StringIO()) as fake_out:
+            print(codestream.segment[2])
+            actual = fake_out.getvalue().strip()
+        self.assertEqual(actual, fixtures.issue_186_progression_order)
+
     def test_crg(self):
         """verify printing of CRG segment"""
         filename = opj_data_file('input/conformance/p0_03.j2k')